Must-Watch Mystery Movie Hidden Gems Free On Amazon Prime

We know you love mystery movies as much as we do. You're always on the hunt, trying to track down that next killer whodunnit. Well, we're happy to report that there's been a break in the case, a new suspect that you might want to look into: Amazon Prime.

In addition to the seemingly endless catalog of films that Amazon Prime has available for purchase, they also have an vast array that are free to watch with an Amazon Prime membership, including an excellent selection of lesser-known mysteries — if you know what to search for. Some of these hidden gems are independent films that never really made a big splash in theaters. Others are slightly older films that have faded a bit from cultural memory, but are nonetheless awesome. And finally, some are strange cult classics that you simply have to see to believe. Some are traditional detective-driven mysteries; others are far stranger movies that exist at the fringes of the genre, including comedy mysteries, horror mysteries, science fiction mysteries, and even one mystery romance.

After a thorough investigation through all this streaming service's seediest back alleys, we're now ready to present our findings. Which of these hidden gem mystery films will be your new favorite? Any good detective will tell you that it's always the one you least expect.

A Simple Favor

Director Paul Feig is best known for loose improv-driven comedies like Bridesmaids and 2016's Ghostbusters. That's why you might be surprised to learn that, in 2018, he broke from his trademark informal style for the most meticulously crafted film of his career. If you missed A Simple Favor when it was in theaters, check it out. It might be his best work yet.

Anna Kendrick plays lonely single mom Stephanie Smothers. Her best friend Emily, played by Blake Lively, seems to have it all: a lucrative job, a loving husband, and — above all — confidence. One day, Emily asks Stephanie for "a simple favor," to look after her son for a few hours while she deals with a work crisis. Stephanie agrees, and then Emily goes missing. Weeks pass, and there's no sign of her. After the police finally give up the search, Stephanie decides to take the investigation into her own hands. We don't want to ruin any of the later plot twists, so let's just say that, as Stephanie digs deeper, she discovers another side to her friend that she kept hidden from the rest of the world.

Well-written, well-acted, and tastefully sleazy, A Simple Favor is what would happen if Gone Girl was also allowed to be funny sometimes. We really hope this sparks a whole new genre of similar black comedy "Mommy Noir" films, but even if it doesn't, this wonderful gem of a movie is definitely worth a watch.

In the Heat of the Night

In some ways, In the Heat of the Night is hardly an obscure film. It even won the Academy Award for Best Picture the year it came out. Then again, since that year was 1967, there's a fair chance that many younger movie fans haven't even heard of it. Fortunately, its inclusion as a free movie on Amazon Prime means that there's never been a better time to check it out.

Sparta, Mississippi is normally a quiet place, except for the constant simmering racial tensions that come with being a small town in the south during the civil rights movement. Then one night, a wealthy businessman is killed. During the ensuing manhunt, a white police officer comes across a black man named Virgil Tibbs, played by Sidney Poitier, waiting for a train, and despite having no evidence, he arrests Tibbs on suspicion of murder.

Once Virgil is brought back to the police station, he reveals that he too is a police officer — the top homicide detective in Philadelphia. The charges against Tibbs are soon dropped, but before he is let go, the Sparta Police Chief asks for his help on the case, admitting that his department is relatively small and underfunded. Against his better judgment, Tibbs reluctantly agrees to help the all-white — and largely racist — local police force track down the real killer.

With an expertly crafted detective story, cutting social commentary, and a magnetic central performance by Poitier, In the Heat of the Night is a truly timeless classic.

The Handmaiden

Set during the Japanese occupation of Korea, The Handmaiden tells the story of a Korean servant named Sook-hee who is hired by a rich Japanese heiress named Hideko. What Hideko doesn't know is that her new handmaiden has a secret: Sook-hee is actually a skilled thief, the partner of a con artist with the pseudonym "Count Fujiwara." The Count plans to seduce Hideko and steal her fortune, and it's Sook-hee's job to befriend the lady, then persuade her to marry Fujiwara when the proper moment comes. But as Sook-hee gets to know her mistress better, she starts to have second doubts about the Count's dastardly plan.

And that's just the first half hour. From there, things get really wild. We won't spoil anything, but let's just say that Count Fujiwara has been hiding certain facts from Sook-hee about the nature of his plan, and Hideko herself also has her fair share of dark secrets.

Sometimes, mystery films lose a bit of their spark after the first time you see them, once you have all the answers about whodunnit and why. The Handmaiden is such a beautifully constructed and intelligently written film that it just gets better every time you watch it. This multifaceted masterpiece alternates between being thrilling, terrifying, sensual, and hilarious, but it always remains deeply human. A fair warning though: this steamy thriller is not at all for children, as at times it gets very sexually explicit.

Murder on the Orient Express

If you're looking for a classic murder mystery, it doesn't get much more classic than the 1974 film Murder on the Orient Express, an adaptation of the Agatha Christie novel by the same name featuring many of the biggest stars of the '70s, including Albert Finney, Lauren Bacall, Ingrid Bergman, and Sean Connery.

Having just solved a case, famous detective Hercule Poirot is on his way home, aboard the train known as the Orient Express. Poirot spends his evening getting to know a collection of eclectic international passengers, including an arrogant American businessman named Mr. Ratchett. Ratchett approaches Poirot and tells him that he's been receiving death threats lately, and asks the detective if he'd be willing to serve as Ratchett's bodyguard, but Poirot refuses.

In the morning, the passengers discover two chilling surprises. The first is that the train has stopped due to a heavy snowfall blocking the tracks. The second is that Mr. Ratchett has been murdered in his sleep, stabbed in the chest a dozen times. Poirot vows to solve the case, and given that the train can't go anywhere for the time being, he has all the time he needs to conduct a series of interviews with the various passengers about their potential motives.

Poirot slowly puts together the pieces of what is most assuredly one of the most absurdly complex and multi-layered locked room mysteries in the history of detective fiction — and one that we're sure you'll never forget.

Blow the Man Down

Many of the movies we're discussing here are older films, classics of the mystery genre. If you're looking for a more recent movie, how about one that was released in March 2020, direct to Amazon Prime?

Blow the Man Down opens in the small town of Easter Cove, where straitlaced sisters Priscilla and Mary Beth are attending their mother's funeral. After the ceremony, Mary Beth visits a bar to drown her sorrows, and while there she meets a handsome stranger. This man, however, isn't everything he seems, and their encounter ends with Mary Beth accidentally implicated in a terrible crime. She calls her sister for guidance, and Priscilla agrees to help erase the evidence of what Mary Beth has done.

As the two sisters work to keep their own secret hidden, they end up discovering the secrets of some of their neighbors, uncovering a dark criminal underbelly of their sleepy hometown. They soon find themselves surrounded by an array of deadly enemies, and perhaps also some new unlikely allies.

There's so much to love about Blow the Man Down. It's beautifully shot and smartly written, but perhaps best of all is the acting, including a pair of show-stealing performances by Margo Martindale and GLOW actress Gayle Rankin in supporting roles. If you're somewhat underwhelmed by the film's sluggish first act, stick with it. Blow the Man Down really kicks into high gear about half an hour in, and it's one hell of a ride from there to the finish.

Blue Velvet

If you've seen a David Lynch movie before, you know that simply summarizing the plots of his films doesn't do them justice. That being said, we'll do our best to describe in words this movie that cannot be explained, only experienced. Let's talk about Blue Velvet.

While walking home one day, lovably square college student Jeffrey Beaumont finds a severed human ear lying in a vacant lot. He immediately hands it over to the police, but he isn't able to stop thinking about how it got there, and starts investigating the mystery alongside his friend Sandy Williams, the daughter of a police detective.

Jeffrey decides to sneaks into the apartment of a woman believed to be connected to the case, and once inside... let's just say that he discovers he's been living on the precipice of a vast darkness, and now he's tumbled headfirst over the edge into a cruel and disturbing world that he might never be able to fully return from.

Like all of Lynch's films, Blue Velvet is surreal, funny, and darkly mesmerizing. That being said, it's also, at times, intensely disturbing, containing some brutally explicit scenes of rape and violence shown with unflinchingly clarity. If you're not willing to sit through that, then this is not a movie for you. We encourage you to do what Jeffrey should have done — leave this particular severed ear of a film lying on the ground and proceed on with your life as if you never found it.

The Conversation

The Conversation tells the story of Harry Caul, a private security expert who lives a life of isolation, deliberately avoiding developing close relationships with the people in his life for fear of his own security. Although Caul is frequently hired to record the conversations of strangers, he tries not to pay attention to the subject matter or think about the way his work could be used to hurt people.

One day, Harry is hired by a mysterious client to record a young couple's conversation as they walk through a public park. Afterwards, Caul gets a bad feeling about the job. Fearing the couple may be in danger, he decides to hold onto the tapes rather than hand them over to the client. As Caul continues to analyze the recording, searching for additional information on who this couple is and what his mysterious client wants with them, he begins to suspect that he himself is being followed, and that his conversations are now being bugged.

By some definitions, The Conversation doesn't really qualify as a traditional mystery. There's certainly a compelling question at the heart of it, but it lacks many of the other traditional elements of the genre. It's slow, moody, and far more of a character study than a regular whodunnit. But nonetheless, it's a truly captivating story, so if you've got a hankering for some moody wood-paneled '70s noir, and we highly recommend checking it out.

Annihilation

If you like a little horror mixed in with your mystery, you should definitely check out the beautiful and enigmatic sci-fi thriller Annihilation.

Natalie Portman plays Lena, a biologist and former soldier. One night, her husband, a soldier named Kane, mysteriously appears in their house with no idea how he got there, despite the fact that he was allegedly away on a classified assignment. He then collapses, seemingly ill. Government forces soon arrive on the scene, and they take Lena and Kane to a government facility.

Once there, Lena is told that they are on the border of an enigmatic region of American coastline that has been designated "the Shimmer." Inexplicable phenomena have been occurring in the area, and any soldiers who enter the Shimmer never return — except for Lena's husband, who remains in critical condition. Another team is assembled to explore the Shimmer, and Lena volunteers to come along. Her team then enters a strange glittering landscape, where the plants and animals have mutated into new beautiful and deadly alien species. As they venture deeper into the Shimmer, Lena's team begins to suspect that their bodies and minds are starting to change as well.

Despite being a mind-blowingly beautiful and thought-provoking film, Annihilation was a bit of a box-office dud. That means that, statistically speaking, you probably didn't see it in theaters. Shame on you. You must now repent by watching Annihilation for free, right now, on Amazon Prime.

Charade

Some people dislike older films, believing them to be, as a rule, slowly paced. If you're one such person, give Charade a chance to prove you wrong. Despite being from 1963, this classic mystery starts with a bang and doesn't let up for the entirety of its runtime.

While on a skiing trip, Regina Lampert (Audrey Hepburn) meets a charming stranger named Peter Joshua (Cary Grant). There is an instant spark between them, but since Regina is married to a man named Charles, she decides not to pursue him further. After Regina returns home, she finds that Charles has been killed. Shortly after, a trio of thuggish men begin to tail Regina, apparently after a fortune that they believe her husband stole from them before his death. Then, as Regina flees from her three pursuers, while also searching for her husband's missing money, she once again crosses paths with the dashing Peter Joshua. After she explains her situation, he agrees to stay by her side and protect her. But why does she keep running into him? Are his motives really as pure as he claims, or is there another side to him?

Equal parts murder mystery, spy thriller, and screwballl comedy, Charade is as good as movies get. It's as faced-paced, efficient, and gripping as any film made in the six decades since its initial release. Even if you're a seasoned movie fan, we promise you that you won't see some of this movie's wild plot twists coming.

The Lighthouse

Though some of these mystery movies are older classics, our next selection is from 2019 — though you won't be able to tell by looking at it. The Lighthouse was shot in black and white, using camera lenses from the 1930s and an almost square aspect ratio of 1.19:1 that harkens back to the days before widescreen. If Willem Dafoe and Robert Pattinson weren't the two leads, you might really think it was a hundred-year-old film.

Sometime in the 1890s, two men arrive on a remote island: seasoned lighthouse keeper Thomas Wake (Dafoe) and his new apprentice Ephraim Winslow (Pattinson). The men have a four-week contract to maintain the island's lighthouse, and apart from each other, they'll be utterly alone.

Ephraim and Thomas try to be friends at first, but continually end up butting heads over their duties. Ephraim also learns that Thomas' last assistant apparently died after losing his mind, raving about seeing merfolk, and believing "that there was some enchantment in the light." Over the following weeks, Ephraim himself begins to see inexplicable things which he keeps hidden from Thomas — then a storm hits the island, and everything gets much worse.

If the captivating script and the dynamite acting weren't enough, both are elevated to truly memorable heights by The Lighthouse's tremendous cinematography within its claustrophobic aspect ratio. It's the perfect choice for a film all about verticality, where you often feel like you're not seeing the whole picture.

Clue

If midway through your mystery binge, all these dour stories about murder and the dark side of humanity have got you feeling down, why not try lightening the mood a little with this last selection? Based on the classic board game, the 1985 film Clue is equal parts classic murder mystery and ensemble comedy farce.

Six strangers are gathered together for a dinner party in a swanky New England mansion by a mysterious man named Mr. Boddy. During dinner, the lights go out; when they come back on, the six guests find that Boddy has been murdered. Before the night is over, this motley crew needs to figure out which one of them is the killer before they can escape and kill again.

With a cast consisting of Tim Curry, Christopher Lloyd, Madeline Kahn, Michael McKean, and more hilarious actors all at the top of their game, Clue is a truly great comedy, but that's not all. It's also a genuinely solid murder mystery, surprisingly complex and layered (y'know, for a movie based on a board game). But above all, it's just plain fun. If you haven't seen it before, do yourself a favor. There's a reason that this little film became a late-night comedy cult classic.